Separation of organic compounds



Sept. 20, 1966- v. MORTIMER SEPARATION OF ORGANIC COMPOUNDS 5 Sheets-Sheet 1 Filed Sept. 12, 1963 INVENTOH JOHN VICTOR MORTIMER MORGAN, FINNEGAN, DURHAM O PINE ATTORNEYS Sept. 20, 1966 v. MORTIMER SEPARATION OF ORGANIC COMPOUNDS 5 Sheets-Sheet 2 Filed Sept. 12 1963 INVENTOR ,JOHN VICTOR MORTIMER MORGAMFINNEGAN, DURHAM 8 PINE ATTORNEYS Sept. 20, 1966 J. v. MORTIMER 3,273,315

SEPARATION OF ORGANIC COMPOUNDS Filed Sept. 12, 1963 5 Sheets-Sheet 5 INVENTOR ,JOHN VICTOR MORTIMER MORGAN, FINNEGAILDURHAM B PINE ATTORNEYS United States Patent 3,273,315 SEPARATION OF ORGANIC COMPOUNDS John Victor Mortimer, Sunhury-on-Thames, England, as-

signor to The British Petroleum Company Limited, London, England, a British joint-stock corporation Filed Sept. 12, 1963, Ser. No. 308,397 Claims priority, application Great Britain, Sept. 25, 1962, 36,388/62; Dec. 3, 1962, 45,480/62 16 Claims. (Cl. 55-67) This invention relates to an improved active constituent for use in a column in which a mixture of organlc compounds is to be resolved.

The invention also relates to an improved process for the separation of organic compounds by passing them through a packed column containing an active constituent.

It has been disclosed that mixtures of aromatic hydrocarbons may be resolved by eluting them tln'ough a column containing a packing consisting of dimethyldioctadecylammonium bentonite and kieselguhr, but in order to achieve satisfactory resolution it has hitherto been necessary to work with extremely small quantities of material (ca. 0.02 microlitre). In order to detect the resolved components of a mixture from such quantities it has hitherto been found necessary to employ high sensitivity ionisation detectors.

Such small quantities of material are inconvenient to handle and, if intended as samples for analysis, it is difficult to ensure that they are truly representative of the mixtures from which they are taken.

According to one aspect of the present invention there is provided an active constituent for use in the resolution of a mixture of organic compounds by a gas chromatographic process, the constituent comprising a mixture of (a) an organo-clay compound in which some or all of the replaceable inorganic cations present in a clay compound capable of interlamellar expansion are replaced by organic cations, the organo-clay compound being in particulate form and (b) a modifying agent therefor, the modifying agent being a substance which is, or at process operating temperatures will be, a liquid which is of low volatility whereby no substantial amount of the liquid is volatilised in use, which is a solvent for at least one of the components of the mixture and which does not react chemically with the organo-clay compound or with the components of the mixture to be resolved.

Suitable organo-clay compounds include organo-montmorillonoids, and organo-nontronites.

The preferred organo-clay compounds are organo-montmorillonites, especially organo-bentonites.

Preferably the organic cation is a quaternary ammonium ion containing long chain alkyl groups or both alkyl and aryl groups.

Most preferably the organo-clay compound is dimethyl dioctadecyl ammonium bentonite.

Suitable modifying agents may be selected from hydrocarbons, halogenated hydrocarbons, alcohols, glycols, phenols, esters, ketones, aldehydes, nitriles, amines, organic nitro compounds, organic carbonates, organic sulphonates, organic phosphates and organopolysiloxanes. Mixtures of compounds may be employed, for example, petroleum fractions, e.g. lubricating oil fractions. Suitable organopolysiloxanes include phenyl methyl and dimethyl silicones.

' Preferably the mixture comprises from 0.2 to 3, most preferably from 0.3 to 2.0, parts by weight modifying agent per part by weight organo-clay compound.

Preferably the mixture is supported on an inert solid, suitably kieselguhr.

Preferably the supported mixture consists of particles capable of passing 30 mesh B.S.S. but retainable by 150 mesh B.S.S.

Suitably the ratio by weight of mixture to inert solid is in the range 1:20 to 1:3. Preferably the ratio is in the range 1.3110 to 3:10.

According to another aspect of the invention there is provided a process for the separation of organic compounds from a mixture of organic compounds which process comprises subjecting the mixture to gas chromatography using as an active constituent the active constituent as hereinbefore described.

The particular modifying agent or agents, and the proportions thereof relative to the organo-clay compound, to be employed in any particular separation process may be determined from a knowledge of the components of the mixture to be separated and the temperatures at which separation is to be effected.

The mixture to be resolved may be subjected to gas chromatography at a temperature up to and including 200 C.

Suitable gases which may be employed as eluents in the process include helium, argon, nitrogen, hydrogen, carbon dioxide and air.

The process of this invention is suitable for the separation of mixtures of hydrocarbons and/or substituted hydrocarbons and, in particular, mixtures of hydrocarbons of closely related boiling point. Thus the process may be used for the resolution of narrow boiling aromatic hydrocarbon fractions and is particularly suitable for the separation of the C aromatic isomers.

The invention is illustrated by, but not limited With reference to, the following examples:

Example 1 An active constituent was prepared by mixing 3 gm. of Bentonite34, a form of dimethyl dioctadecyl ammonium bentonite, with 3 gm. silicone oil MS 555, a phenyl methyl silicone, and dispersing the mixture in 30 ml. of benzene. The resulting dispersion was then added to a dispersion of 30 gm. Embacel, a form of kieselguhr, in 200 ml. benzene. The benzene was removed by evaporation while the mixture was stirred continuously. The evaporation was terminated under vacuum.

Bentone-34, and Embacel are registered trademarks.

Some of thematerial prepared above was packed into a copper column. The column was 12 ft. long and had an outside diameter of 0.25 in. and a wall thickness of 20 s.w.g. The packing density was 1.85 gm. material per foot length of column.

A sample mixture of 17 hydrocarbons was then eluted through the column under the operating conditions set out in Table 1. Helium was used as an eluent and a thermistor detector was employed.

A further sample mixture of 23 hydrocarbons was then eluted through the column described with reference to Example 1 under the operating conditions set out in Table 2, again using helium as an eluent and employing a thermistor detector.

TABLE 2 Column temperature C. Inlet pressure 22 p.s.i.g. Flow rate helium 106 ml./min.

Sample volume 5 microlitres.

Example 3 An active constituent was prepared by mixing 3 gm. of Bentone-34, a form of dimethyl dioctadecyl ammonium bentonite, with 1.5 gm. polyethylene glycol and dispersing the mixture in 30 ml. of benzene. The molecular weight of the polyethylene glycol was approximately 400. The resulting dispersion was then added to a dispersion of 30 gm. Embacel in 200 ml. benzene. The benzene was removed by evaporation while the mixture was stirred c-ontinu-ously. The evaporation was terminated under vacuum.

Some of the material prepared above was packed into a copper column. The column was 12 ft. long and had an outside diameter of 0.25 in. and a wall thickness of 20 -S.W.G. The packing density was 1.98 gm. material per foot length of column. The packing consisted of particles capable of passing 60 mesh B.S.S. but retainable by 100 mesh B.S.S.

A sample of a mixture of six hydrocarbons was then eluted through the column under the operating conditions set out in Table 3. Helium was again used as an eluent and a thermistor detector was again employed.

TABLE 3 Column temperature 70 C. Inlet pressure 28 p.s.i.g. Flow rate helium 58 ml./ min. Sample volume 3 microlitres.

Example 4 An active constituent was prepared by mixing 3 gm. of Bentone34 with 3 gm. squalane and dispersing the mixture in 30 ml. of benzene. The resulting dispersion was then added to a dispersion of 30 gm. Embacel in 200 ml. benzene. The benzene was removed by evaporation while the mixture was stirred continuously. The evaporation was terminated under vacuum.

Some of the material prepared above was packed into the copper column described with reference to Example 1. The packing density was 2.0 gm. material per foot length of column. The packing consisted of particles capable of passing 60 mesh B.S.S. but retainable by 100 mesh B.B.S.

A sample of a mixture of six hydrocarbons was then eluted through the column under the operating conditions set out in Table 2. Helium was again used as an eluent and a thermistor detector again employed.

TABLE 4 Column temperature 100 C. Inlet pressure 30.5 p.s.i.g. Flow rate helium 70 ml./ min. Sample volume 3 microlitres.

Example An active constituent was prepared by mixing 3 gm. of Bentone-34 with 3 gm. tolyl phosphate and dispersing the mixture in 30 ml. benzene. The resulting dispersion was then added to a dispersion of 30 gm. Embacel in 200 ml. benzene. The benzene was removed by evaporation while the mixture was stirred continuously. The evaporation was terminated under vacuum.

Some of the material prepared above was packed into a column. The column was 8 ft. long and had an outside diameter of 0.25 in. and a wall thickness of 20 S.W.G.

A sample mixture of ortho-, paraand meta cresol was then eluted through the column under the operating conditions set out in Table 1. Helium was again used as an eluent and a thermistor detector again employed.

TABLE 5 Column temperature 140 C. Inlet pressure 28 p.s.i.g. Sample volume 3 microlitres.

The invention is further illustrated by the accompanying drawings of which FIGS. 1 and 2 are chromatograms of the mixtures eluted as described with reference to Examples 1 and 2. FIGS. 3, 4 and 5 of the accompanying drawings are chromatograms of the mixtures eluted as described with reference to Examples 3, 4 and 5.

With reference to FIGS. 1 and 2:

Column peaks (124) represent the following components of the mixture: (1) air; (2) isopentane; (3) n-pentane; (4) n-hexane; (5) cyclohexane; (6) n-heptane; (7) methyl-cyclohexane; (8) benzene; (9) n-octane; (10) toluene; (ll) n-nonane; (12) ethylbenzene; (13) p-xylene; (14) m-xylene; (15) o-xylene; (16) isopropylbenzone; (17) styrene; (18) n-propylbenzene; (l9) l-methyl- 4-ethylbenzene; (20) 1-methyl-3-ethylbenzene; (21) lmethyl-Z-ethylbenzene; (22) 1,3,S-trimethylbenzene; (23) 1,2,4-trimet-l1ylbenzene and (24) 1,2,3-trimethylbenzene.

With reference to FIGS. 3 and 4:

Column packs (25-31) represent the following components of the mixtures: (25) air; (26) benzene; (27) toluene; (28) ethylbenzene; (29) p-xylene; (30) m-xylene and (31) o-xylene.

With reference to FIG. 5;

Column peaks (32-34) represent the following components of mixture: (32) ortho-cresol; (33) para-cresol, and (34) meta cresol.

I claim:

1. An active constituent for use in the resolution of a mixture of organic compounds by a gas chromatographic process, the constituent comprising a mixture supported on an inert solid, said mixture being (a) organo-clay compound in which at least some of the replaceable inorganic cations present in said clay compound capable of inter lamellar expansion are replaced by organic cations, the organo-clay compound being in particulate form, and (b) a modifying agent therefor, the modifying agent being a substance of low volatility which at process operating temperatures will be a liquid whereby no substantial amount of said liquid is volatilised in use at process operating temperatures, which is a solvent for at least one of the components of said mixture of organic compounds to be resolved and which does not react chemically with the organo-clay compound and with the components of the mixture to be resolved.

2. An active constituent according to claim 1 wherein the organo-clay compound is a compound selected from the group consisting of organo-montmorillonoids and organo-nontronites.

3. An active constituent according to claim 1 wherein the organo-clay compound is an organo-montmorillonite.

4. An active constituent according to claim 3 wherein the organo-montmorillonite is an organic-bentonite.

5. An active constituent according to claim 4 wherein the organic cation of the organic-bentonite is a quaternary ammonium ion containing long chain alkyl groups.

6. An active constituent according to claim 5 wherein the organo-bentonite is dimethyl dioctadecyl ammonium bentonite.

7. An active constituent according to claim 1 wherein the modifying agent is seletced from the group consisting of hydrocarbons, halogenated hydrocarbons, alcohols, glycols, phenols, esters, ketones, aldehydes, nitriles, amines, organic nitro compounds, organic carbonates, organic sulphonates, and organic phosphates.

8. An active constituent according to claim 1 wherein the modifying agent is an organo poly siloxane.

9. An active constituent according to claim 8 wherein the organo poly siloxane is selected from the group consisting of phenyl methyl and dimethyl silicone.

10. An active constituent according to claim 1 wherein the active constituent comprises from 0.23 parts by weight modifying agent per part by weight organo-clay compound.

11. An active constituent according to claim 10 wherein the active constituent comprises from 0.3-2.0 parts by Weight modifying agent per part by Weight organo-clay compound.

12. An active constituent according to claim 1 wherein the inert solid is kieselguhr.

13. An active constituent according to claim 1 wherein the active constituent and support consists of particles capable of passing 30 mesh B.S.S. but retainable by 150 mesh B.S.S.

14. An active constituent according to claim 1 wherein the ratio by weight of active constituent to inert solid is in the range 1:20 to 1:3.

15- An active constituent according to claim 14 wherein the ratio by Weight of active constituent to inert solid is in the range 1.3:10 to 3:10.

16. A process for the separation of organic compounds from a mixture of organic compounds which process comprises subjecting the mixture to gas chromatography using as an active constituent the active constituent of claim 1.

References Cited by the Examiner UNITED STATES PATENTS OTHER REFERENCES White, D., et al.: The Sorption Properties of Dimethyidioctadecyl Ammonium Bentonite Using Gas Chromatography, in Trans. Faraday Soc. 54 (4), pp. 557-561 (195 8).

Van Swasy: Gas Chromatography, Butterworths, Washington, D.C., 1962, pp. 111-116.

REUBEN FRIEDMAN, Primary Examiner.

C. N. HART, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No; 3,273,315 September 20, 1966 John Victor Mortimer It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 36, for "of Bentonite-34" read of Bentone-34 column 4, line 52, for "is an organic bentonite" read is an organo-bentonite Signed and sealed this 22nd day of August 1967 (SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. AN ACTIVE CONSTITUENT FOR USE IN THE RESOLUTION OF A MIXTURE OF ORGANIC COMPOUNDS BY A GAS CHROMATOGRAPHIC PROCESS, THE CONSTITUENT COMPRISING A MIXTURE SUPPORTED ON AN INERT SOLID, SAID MIXTURE BEING (A) ORGANO-CLAY COMPOUND IN WHICH AT LEAST SOME OF THE REPLACEABLE INORGANIC CATIONS PRESENT IN SAID CLAY COMPOUND CAPABLE OF INTER LAMELLAR EXPANSION ARE REPLACED BY ORGANIC CATIONS, THE ORGANO-CLAY COMPOUND BEING IN PARTICULATE FORM, AND (B) A MODIFYING AGENT THEREFOR, THE MODIFYING AGENT BEING A SUBSTANCE OF LOW VOLATILITY WHICH AT PROCESS OPERATING TEMPERATURES WILL BE A LIQUID WHEREBY NO SUBSTANTIAL AMOUNT OF SAID LIQUID IS VOLATILISED IN USE AT PROCESS OPERATING TEMPERATURES, WHICH IS A SOLVENT FOR AT LEAST ONE OF THE COMPONENTS OF SAID MIXTURE OF ORGANIC COMPOUNDS TO BE RESOLVED AND WHICH DOES NOT REACT CHEMICALLY WITH THE ORGANO-CLAY COMPOUND AND WITH THE COMPONENTS OF THE MIXTURE TO BE RESOLVED. 